Migration to typeconv

[dchiu911]

Hi @samuelcyleung the following steps can be performed in data packages to migrate from using package-specific to_native_type() implementations to the one in typeconv::to_native_type():

• in DESCRIPTION, add:
  • Imports: typeconv
  • Remotes: TalhoukLab/typeconv
• in the data package, simply change the to_native_type() function body to typeconv::to_native_type(x) and remove all S3 methods